1. Field of the Invention
The invention relates generally to improvements in form and construction of trailer hitch assemblies of the longitudinal draw bar type wherein a resilient spring load is interpositioned to transmit forces between the hitch ball and the towing vehicle thereby to significantly dampen shock vibrations.
2. Description of the Prior Art
Prior art forms of vehicle trailer hitch assembly are many and diverse as developed over a long period of years. There are some types which attempt to incorporate some form of resilient vibration damping device in the hitch tongue, i.e. the draw bar of the towed vehicle. An example of such prior teachings is exemplified by U.S. Pat. Nos. 2,189,170 and 3,961,813, but there are also many other types of draw bar damping device that have been utilized. Some other patents have sought to construct a vibration damping device that is secured to the tow vehicle. U.S. Pat. No. 1,819,393 discloses a form of damping device that is rigid with the towing vehicle and attempts to damp all vibrations from the towing connection by suspending the tow shaft in resilient mounting. Another form of vibration mounting as secured to the vehicle is taught by U.S. Pat. No. 1,816,121 which utilizes a plural spring arrangement as connected through the draw bar or portion of bumper. U.S. Pat. Nos. 3,843,162 and 4,265,465 teach additional types of spring arrangement wherein the spring assembly is secured to the towing vehicle albeit that these structures and their attendant function differ in various ways from the teachings of the present invention.